Nitratiruptor sp. (strain SB155-2) is a genus of deep sea gram-negative Campylobacterota isolated from Iheya North Hydrothermal field in Okinawa Trough (Japan). This rod-shaped microorganism (0.5 x 1.5 μm) grows chemolithoautotrophically in a wide variety of electron donors and acceptors (i.e. sulfur, hydrogen, oxygen and nitrate) in absence of light and oxygen. It is also a thermophilic group capable of growing within the range of 37–65 °C with the optimal at 55 °C.
